There's that but then there's also the idea that you don't hit truly verticle. I will always punch slightly downwards if I have the opportunity. Same thing for round kicks right? Don't you like your kicks to cut downwards on impact as opposed to rising up? You want your body weight to drop just at the moment of impact. Think of is as the opposite of floating up on your punches. You drop down.

So you're saying the effect is:

?

I think this one might be the stronger, in terms of power contribution.

To practice coordination, do you start from slow to fast on the same motion, or do you build up your body to perform each component well, and then just work on timing?

If it was just a matter of dropping you weight, you wouldn't need everything to be as coordinated.

Dropping your weight is a matter of coordination, in terms of timing.
You can do it sharply, which means your muscles holding you up would loosen and let you get to freefall faster.
Or you could (I would consider this the much poorer way to do it) gradually do it, which means you gradually increase your downward acceleration, which means your downward velocity takes longer to build up.

Feet and hands should arrive at the same time when striking. It helps with coordinating the body mechanics and puts more mass behind the strike. I don't do Baji so I don't know the specifics, but the xyingyi I am learning we don't stomp down hard per se but we do land foot and fist at the same time. Then depending on the situation or which posture we are doing, we add a follow step. It supposedly adds a second pulse to the strike. I have felt what a stationary fist plus a follow step feels like and there is a jolt added by the step. BTW, Meng where did you find that first diagram? It looks really familiar for some reason.

The idea sounds similar to shooting a jab in and dropping as you do it to get a little more distance and a little more oomf in the jab. If it's an actual "stomp" though, where you come down heavy on the foot and land flat footed, it would seem to me that you'd end up leaving yourslef out there, unable to pop back easily like if you did it the boxing way (push off the back foot, then pop back with the front foot, staying on the balls of your feet).

Yes. That's a common problem. One I am actually dealing with. Well...not damaged AFAIK anyways but a but sore as of last week. My teacher insists that I practice on grass or dirt as that is supposed to protect your knees. I have been a bit stubborn and found it hard to make time to get to a park so I typically practice in my living room. I live on the ground floor but the floor is tiled on top of cement. One week I spent several days in a row commited to doing 100 reps each of various moves complete with the stomp. . . .now my right knee has been bothering me for about 2 weeks. *shudder* It's not so crazy really. Just running can **** up your knees if you do it on concrete instead of asphalt or better yet, a dirt path.

I've been warned so I can't even blame the method as I was told endless times not to train the stomping on a cement surface.

Originally Posted by Kidspatula

The idea sounds similar to shooting a jab in and dropping as you do it to get a little more distance and a little more oomf in the jab. If it's an actual "stomp" though, where you come down heavy on the foot and land flat footed, it would seem to me that you'd end up leaving yourslef out there, unable to pop back easily like if you did it the boxing way (push off the back foot, then pop back with the front foot, staying on the balls of your feet).

Very similar. Same general idea. The difference though is that it is not a jab generally. The more typical thing is to be slamming your torso into the other guy. The hand goes out but the real intent is often not in the hand but at the chest or shoulder. The best metaphore I know is like when a fight breaks out in a hockey match and they go slamming into each other body to body so you don't really worry about retracting as presumably you have just placed yourself close enough to smell what the other guy had for lunch. "kissing close". Now you have either knocked the guy over, away or are essentially in throwing/sweeping range. Your hips are touching his. You might punch but the basic intent behind most everything is to put yourself that close to the other person.

Anything about knee damage? If you do hard stomps, does that hurt your knees in the long run?

Yes. I'm recovering from a knee injury acquired that way right now. To be fair, though, I'm 6'5" and big, so my knees were not in sterling shape in the first place. Other people in my class haven't been hurt this way.

Just running can **** up your knees if you do it on concrete instead of asphalt or better yet, a dirt path.

I've been warned so I can't even blame the method as I was told endless times not to train the stomping on a cement surface.

The right footwear can help a lot with the running.
Do you train in Chinese plastic sole type shoes, or always the sneakers that I see in the videos? In general, I'm uneasy about fighting in different shoes, since I usually train barefoot or in socks. The few times I've hit the heavy bag in shoes, I've always been quite off.